Device for cold welding exhaust tubulations



1959 GJJ. AGULE ETAL 2,896,483

mavxcsron cow WELDING EXHAUSTTUBULATIONS Fild June 1. 1954 sSheets-Sheet 1 FIG. I

INVENTORS GEORGE J. AGULE and ALBERT F ENGLER TORNEY Jul 28, 1959 G. J.AGULE ETA]. DEVICE FOR cow WELDING EXHAUST TUBULATIONS Filed June 1.1954 3 Sheets-Sheet. 2

INVENTORS M M R m Y MT R GE A AF m J Q m T uwR RE 8 EL GA Y B July 1959I J. AGULE ET AL 2,896,483

osvzcs FOR cow WELDING EXHAUST TUBULATIONS Filed Jude 1. 1954 I sSheets-Sheec a INVENTORS GEORGE J. AGULE and ALBERT EQENGLER AT ZRN EYed S ate Pat I JEVICE FOR COLD WELDINGEXHAUST .TUBULATIONS ApplicationJune 1, 1954, Serial No. 433,601

1 Claim. (CI. 78-82) V This invention concerns a novel pinch-off devicefor exhaust tubulations such as are used on electron tubes in order topermit them to be connected to an exhaust pump. More specifically, thisinvention consists of a pinch-off device which will properly positionitself relative to the exhaust tubulation which is to be pinchedoil sothat no mechanical damage can be caused the exhaust tubulation or theenvelope to which it is attached.

It has become common in the electron tube industry and elsewhere wherevacuum-tight or gas-tight sealing off is required to employ a metallicexhaust tubulation which may be sealed vacuum-tight or gas-tight bymechanically pinching together its side 'walls into a cold weld. Such anexhaust tubulation is advantageously composed of copper and. ispinched-off by using a pair of rounded jaw pinchers as described in US.Patent No. 2,427,597, the invention of Garner. sealing off tubulationshas proved extremely useful and has accomplished great savings in bothtime andmoney.

One problem which has been encountered with manually operated pinchoffdevices of the sort suggested by This method of Gamer has been thetendency for the operator to twist i the pliers or apply uneven forcesto the pliers. As a consequence the tubulation may break or the tubestructure may be damaged due to these undesirable forces applied to itwhile pinching it off. However, to date only hand pinchers or pliershave been employed and Patented July 28, 1959 present invention ispreferably hydraulically actuated so that it will be capable ofpinching-01f tubulations of great size. This is particularlyadvantageous because heretofore in pinching-01f tubulations of greatsize, the additional amount of force required caused the operator to usemuch more strength. Such additional tax on the strength of the operatormight lessen his control and when misapplied could more readily causedamage to the tubulation or the envelope to which it is attached thanwould be the case were the relatively small amounts of force used withsmall tubulations misapplied. The hydraulic unit is capable ofpinching-01f tubulations of any size with essentially the same case withwhich it will pinch-off the smallest tubulation.

A small degree of self-adjustment of one of the jaws may be provided inthe structure of the present invention so that the jaws may adjust toremain essentially parallel to one another throughout the pinchingoperation. If the jaws become sufliciently out of parallel, asatisfactory cold weld is not obtained all the way across thetubulation. Because it is the nature of the preferred construction ofthe present invention to lend support at one side of the jaws, if theforces become sutficient, the support may yield so that fixed jaws willnot be exactly parallel. If provision is made for self-adjustment,however, the jaws will tend to maintain parallelism because the tendencyto distribute forces evenly over the supporting opposed surfaces willproduce such a result, Thus, it is possible to insure complete seal offeach time by use of the self-adjusting jaws. The device of the presentinvention may be made quite flexible byproviding for its elevation todifierent heights so that the jaws may be at the desired level forpinching-off. A preferred way to produce this elevation is to employlegs for the frame which are pneu mantically actuated cylinders whereinadditional air pressure will cause an increase in the length of the leg.

Another feature of the present invention which adds to its flexibilityand usefulness is the flexible mounting device whereby the support forthe jaws is coupled by flexible yieldable mounting members to the frameso that a small amount of vertical adjustment is possible. Such verticaladjustment prevents damage to the tube structure as the tubulation ispinched-off due to forces which occur in the axial direction due toelongation of the tubulation.

may be used to automatically pinch-off exhaust tubula- 1" jaws,preferably composed of a hard material. like tungsten carbide, as taughtby Garner. At least one of these jaws is mounted upon a movable ram. Aframe for supporting the jaws opposite one another is provided so thatthe ram will drive one jaw against the other.

The tubulation to be pinched-off is positioned between the jaws.Finally, the frame is provided with means which will permit freemovement of the frame while maintaining the plane of the jaws. This ismovement relative to the supporting table or reference plane above whichthe tubulation is pinched-off.

In addition to being self-adjusting, the device of the pinchthe legs toraise or lower the height of the pinching jaws relative to thesupporting reference plane.

Fig. 4 illustrates one of the legs showing the flexible coupling betweenthe frame and the support for the jaws. Fig. 5 illustrates in partialsection a flexible coupling between the support and the frame permittingsome vertical yield in the structure.

Referring to the drawings, and in particular to Figs. 1 and 2, it may beseen that the primary frame members 10 and 11 are of C-shape. The twoC-shaped members define a rectangular frame wherein one long side of therectangle is removed. These C-shaped members should have suflicientthickness to be relatively rigid. Said 0- shaped members are connectedby four vertical columns generally designated 12 of identicalconstruction at the four corners of the rectangle. V t

Actual support for the jaws is provided by a support member generallydesignated 15 whichis advantageous- I ly adapted to accept a hydraulicram to form a structure sometimes called a hydraulic C-clamp. Thissupport has a webbed C-shaped connection piece 16 which .interconnectstwo vise-like jaws 17 and 18. These jaws are rounded and areadvantageously composed of tungsten carbide rod mounted so that roundedsurfaces of the two members will abut one another when the jaws areclosed. These jaws may, in turn, be embedded in steel block 19 andpiston 20 of the hydraulic ram. Block 19 and piston 20 advantageouslyembrace more than half the circumference of the cylindrical jaws 17 and18, respectively, and so hold them fast, leaving the exposed areas ofthe jaws for pinching.

The hydraulic ram is composed of a cylinder 21 in which the piston 20rides. The part of piston 20 which accepts jaw 18 may be either anintegral part of the piston or an adapter joined to the piston. Ineither event, fluid is fed into cylinder 21 through coupling 22 in orderto urge the piston out of the cylinder. Cylinder 21 of the hydraulic ramis supported by the support member 15 within its tubular flange 23 whichclosely engages the side walls of said cylinder.

7 Block 19 which supports jaw 17 is supported in fixed anvil-like member25 by means of pin 26 which is snugly accepted by member 25, but looselyengages block 19. Block 19 has a rounded back edge. As may be seen inFig. 1, in order to preserve the alignment'of the jaws, block 19 is freeto shift its position in a sort of swivel motion within the plane of thejaws, as will be described later. Member 25 is cylindrical in shape andhas a shoulder between larger and smaller diameters. The smallerdiameter is accepted by tubular flange of C-support member 15 whichflange snugly engages the smaller diameter portion of anvil member 25 sothat its shoulder is opposed by the tubular flange 33.

Because piston 20 may have a tendency to rotate in its cylinder, therebymisaligning the jaws, it is usually a wise precaution to supply someinterconnecting means 28 to prevent rotation of the jaws. Thisinterconnecting means may consist of a bar which is aifixed to member 25by bolts or other appropriate means. Bar 28, in turn, bears a guide 28awhich is engaged by slot 29 in piston 20. It will be noted that piston20 is generally cylindrical in cross-section except for that part ofpiston 20 which directly engages jaw 18, which part is rectangular insection. The cylindrical portions vary in diameter, the part which isalways outside the cylin der having a diameter larger than the diameterof the cylinder and having groove 29 therein.

C-shaped support 15 is advantageously mounted on frame using mountingbrackets 35 and 36 which may be joined together by cross-link 37.Mounting bracket 35 is advantageously provided with a cylindrical holewhich snugly engages the outside diameter of the cylinder 21 of thehydraulic ram. Bracket 36 is provided with a cylindrical hole whichsnugly engages the cylindrical surface of anvil member 25. V

The mounting brackets may be supported on the frame through specialflexible mounting members, four of which are employed at distributedpoints. As may berseen in Figs. 4 and 5, it is possible that themounting members may extend between the legs 12 and the mountingbrackets or bet-ween the actual frame portion 10 and the mountingbracket. Each of the mounting members consists of an annular flexiblepad 40 of rubber or similar material at whose inside diameter thethickness may be increased to engage sleeve 41 over its entire length.At its outside periphery and embedded in the edge thereof to extendradially is planar annular member 42. The resilient structure formedthereby is supported by passing a bolt 43 through the sleeve andengaging it in a threaded hole in annular bracket 35. The bolt may beheld in place by washer 44 which I prevents the head of the bolt frompressing directly on sleeve 41. Annular ring 42 rests atop frame member10 or leg 12 over an aperture therein so that only the ring 42 touchesthe frame member. The ring 42 may be fixed in place by welding or in anyother suitable manner. This construction'because of the resilient webbetween the ring 42 and the sleeve 41 permits the vertical adjustment ofthe structure. Such adjustment may be necessary when the tubulation iseffectively elongated as it is pinched-off in order to permit the jawsto maintain their position.

The legs of this structure are advantageously cylinders 46 which containa piston member 47 and a pneumatic connection through a manifold linegenerally designated 49. Air pressure may be fed to this manifoldthrough tubing 50 which is connected to a control valve 51 beyond aspeed control valve 52. The various 7 valves and couplings employed inthis pneumatic sysoff on the exhaust tubulation. Raising or lowering thelevel of the jaws is accomplished through the introduction or release ofair within the legs of the structure. The legs may alternatively beadjustable manually or by some means other than pneumatic, hydraulic orother fluid means. The convenience of the pneumatic or a fluid system isimmediately apparent, however. Introduction of the air into the hollowcylindrical legs 46 will cause the piston 47 therein to be driven out ofthe chamber and hence will effectively lengthen the leg. The speedcontrol valve 52 will assure that the lengthening process will not occurabruptly, but rather will occur with smoothness and ease. The controlvalve serves merely to open or close the pneumatic system.

When the-jaws 17 and 18 are at the desired level, the device is movedinto position so that the tubulation lies between the jaws 17 and 18.Stop member 59 held in place by bolts 60 to the frame or the guide 28serves to center the tubulation between the jaws 17 and 18 opposite pin26. Thereafter, the hydraulic ram is actuated by the introduction offluid into the cylinder to drive the ram forward toward the anvil. Asthe ram moves forward, the device moves on its casters 55 and; readjustsits position until the tubulation is square- 1y between the jaws. Thenas the tubulation is squeezed and deformed between the jaws 17 and 18,the position of the frame of the structure is still able to shift torelieve any stresses which might otherwise be imposed upon the exhausttubulation or the structure to which it is connected.

As the jaws are brought together, jaw 17 may tend to move out ofparallel with jaw 18, and it is permitted to do so beacuse of its looseconnection with pin 31.

. However, as the jaws are completely closed, the jaws at the other inresponse to the heavy forces applied. The

centering of the tubulation opposite pin 26 by stop 59 assures properadjustment of the jaws into parallel position.

Many modifications of the structure described will occur to thoseskilled in the art. All such modifications of said structure withinthescope of the claim are intended 5 to be within the scope and spirit ofthe present invention.

We claim:

A device for cold welding and severing exhaust tubulations of electrontubes, comprising a base having a pair of spaced jaw supports thereon,pinching and severing jaws carried by the respective jaw supports, oneof the jaws being movable in a plane in a direction toward the secondjaw to position the jaws in severing engagement with a tubulationtherebetween, means for applying pressure to said movable jaw of anamount sufiicient to pinch the tubulation and to consequently elongatethe tabulation in a direction normal to the plane of movement of themovable jaw, and resilient means connecting the jaw supports to the basewhereby said jaw supports and jaws thereon are simultaneously movable inre sponse to elongation of the tubulation by said jaws in the directionof said elongation and normal to the plane of movement of the movablejaw.

References Cited in the file of this patent UNITED STATES PATENTS672,552 Harrington Apr. 23, 1901 676,292 Wigtel June 11, 1901 851,398Broadbooks Apr. 23, 1907 1,021,501 Bettendorf Mar. 26, 1912 1,165,174Holmes Dec. 21, 1915 1,308,593 Kendall July 1, 1919 1,343,946 WarnerJune 22, 1920 1,556,735 Tiffany Oct. 13, 1925 2,243,013 Morey et a1. May20, 1941 2,421,716 Rose June 3, 1947 2,427,597 Garner et a1 Sept. 16,1947 2,456,125 Iohndrew Dec. 14, 1948 2,555,421 Ronan June 5, 19512,556,000 Temple Aug. 28, 1951 2,675,202 Kaemmerling Apr. 13, 19542,776,473 Bailey et a1. Jan. 8, 1957 OTHER REFERENCES Means ofConnecting Aluminum Conductors" (Barnes), published by McGraw Hill, May1954.

Publication: Shear Type Mountings of Lord Manufacturing Co., Erie, Pa.(Bulletin

